Dermatomyositis-specific auto-antigen

ABSTRACT

The present invention relates to a dermatomyositis-specific auto-antigen, a DNA encoding it and a process for the preparation thereof as well as its use.

This is a division of application Ser. No. 08/913,832, filed Jan. 12, 1998, now U.S. Pat. No. 6,329,517 which is a national phase filing of the Application No. PCT/DE96/00444, which was filed with the Patent Corporation Treaty on Mar. 8, 1996, and is entitled to priority of the German Patent Application 195 09 279.1, filed Mar. 15, 1995.

I. FIELD OF THE INVENTION

The present invention relates to a dermatomyositis-specific auto-antigen, a DNA encoding it and a process for the preparation thereof as well as its use.

II. BACKGROUND OF THE INVENTION

Autoimmune diseases distinguish themselves by the occurrence of autoantibodies, i.e., antibodies directed against constituents of the own organism. Autoantibodies may induce damage of the organism, an organ or part of an organ thus triggering partially serious life-threatening diseases. The origination of such a disease is due to differing pathogenic mechanisms such as neutralization of antigens, e.g. hormones, blocking or stimulation of a receptor for biological active substances, e.g., autoantibodies active against the receptor of the thyroid-stimulating hormone in the case of hyperthyreosis, binding to certain cell or tissue structures accompanied by the induction of a complement-mediated inflammation, e.g., glomerulonephritis, antiautobodies active against glomerulus basement membranes. Tissues damage may also be induced by cell-mediated mechanisms (autoantibody-dependent cellular cytotoxicity) or by localized and systemic immune complex deposits after the binding of the autoantibodies to soluble antigens.

In addition to such obviously directly damaging autoantibodies, a plurality of autoantibodies active against blood, cell or tissue constituents occur in man, to which a tissue-damaging part cannot be assigned yet clearly by now. The group of rheumatic diseases, particularly the inflammatory rheumatic diseases to which the collagen diseases are attributed, is characterized by the occurrence of numerous autoantibodies. They react, e.g., with antigens of the cell nucleus such as double-stranded DNA, single-stranded DNA, RNA, histones, non-histone proteins, ribonucleoproteins, chromosome-associated antigens, e.g., centromeres or spindle apparatus, or with antigens which are expressed only in certain phases of the cell cycle, e.g., cycline.

The above autoantibodies are found in the case of diseases such as lupus erythematodes, Sjögren's syndrome, mixed connective tissue disease, polymyositis, dermatosclerosis, CREST syndrome, Wegener's granulomatosis and dermatomyositis. They are usually detected by reaction with nuclear extracts from thymocytes of calves or rabbits. Due to this, a differential diagnosis of these diseases, particularly of dermatomyositis, is, however, not possible. But such a diagnosis is a precondition for the selection of treatment.

Therefore, it is the object of the present invention to provide means by which dermatomyositis can be detected by way of differential diagnosis.

III. SUMMARY OF THE INVENTION

The present invention relates to a dermatomyositis-specific auto-antigen, a DNA encoding it and a process for the preparation thereof as well as its use.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the cloning and composition of the 218 kD Mi-2 cDNA SEQ ID NO:1. The upper portion of the illustration shows a restriction map with a scale given in kb. The thick line corresponds to the open reading frame including restriction sites outlined by arrows (H=Hind III; B=BamHI; E=EcoRI; C=ClaI; S=SpHI). The horizontal lines represent isolated clones; the clones sequenced in both mixtures are marked by dots. The two small clones in the lower left-hand corner were obtained according to the RACE protocol. Frohmann et al., 1988, Proc. Natl. Acad. Sci. U.S.A. 85:8998-9002). 1: nt 649-4891; 2: nt 0-958; 3: nt 153-4902; 4: nt 1931-4881; 5: nt 2204-4888; 6: nt 3224-4888; 7: nt 4888;8: nt 3666-6155; 9: nt 3843-6239; 10: nt 3967-6155; 11: nt−178−127; 12: nt−168−127.

FIGS. 2A-D collectively show the nucleotide sequence SEQ ID NO:1 and coding amino acid sequence SEQ ID NO:2 of the 218 kD Mi-2 cDNA. The framed sequences show the seven helicase-specific motifs (I, IA, II, IV, V and VI). The four underlined regions contain 11 potential nuclear target sequences ten of which are localized in three N-terminal regions (region a contains 3 motifs; region b includes 4 motifs and region C comprises 3 motifs). The dotted line (nt 401-431) shows an accumulation of glutamic acid and asparaginic acid residues which might interact electrostatically with chromatin (histones).

FIG. 3 shows a Northern blot analysis of the 218 kD Mi-2 gene expression in HEp-2 cells. RNA samples were separated in accordance with their size by means of formaldehyde agarose gel electrophoresis and hybridized with ³²P-labeled Mi-2 cDNA subject to a high degree of stringency. Lane A: 5 μg total RNA of HEp-2 cells; lane B: 0.3 μg HEp-2 cells poly(A)⁺ RNA. The size of the bands in the autoradiograph corresponds to about 6.8 kb.

FIG. 4 shows a computer-assisted analysis of functional domains of the 218 kD Mi-2 protein. NT: potential nuclear target sequences; CB: potential chromatin-binding region; I-VI: helicase-specific domains. The thick horizontal line in the lower portion of the illustration shows a recombinant protein (rMi-2) which was used for immunological studies. A scale indicating the positions of the amino acids is plotted on the top.

FIG. 5 shows the localization of the 218 kD Mi-2 gene with fluorescence-in situ hybridization (FISH) at the short arm of the human chromosome 12 (12p 13) (arrows).

FIG. 6 shows immunoblots of SDS-PAGE-separated (A) recombinant Mi-2 polypeptide (rMi-2) and (B) nuclear proteins of HEp-2 cells which reacted with human sera and rabbit sera and affinity-purified anti-rMi-2-Ig. Lanes Al, B1: human non-reactive control serum. Lanes A2, B2: human anti-Mi-2-positive serum No. 1 (TABLE I) recognizes the rMi-2 with 55 kD (lane A2) as well as the natural 235 kD protein (lane B2) and an additional second natural. nuclear protein having 80 kD. Lanes A3, B3: affinity-purified antibodies of serum No. 1 (human anti rMi-2-Ig) react with both the rMi-2 used for affinity purification and the natural 235 kD nuclear protein. The specificity of the antibody preparation is demonstrated in exemplary fashion by the absent reaction with the 80 kD protein. Lane A4, B4: non-reactive rabbit pre-immune serum. Lanes A5 and B5: following immunization with rMi-2, the rabbit serum recognizes the recombinant antigen (rMi-2) and the natural 235 kD protein. Lanes A6 and B6: affinity-purified rabbit antibodies (rabbit anti-rMi-2-Ig) also react with both proteins, the recombinant antigen and the natural 235 kD protein. Lane C (control): core proteins of HEp-2 cells react with a plurality of human antibodies.

FIG. 7A shows immunoblots of nuclear (N), mitochondrial (Mt), microsomal (Ms) and cytoplasmic (S-100, S) fractions (80 μg protein/cm) of HEp-2 cells which reacted with affinity-purified rabbit-anti-rMi-2 antibodies. The 218 kD Mi-2 protein was found almost exclusively in the nuclear fraction at M_(r)=235 kD. A very small portion of immunoreactive protein can be recognized in the S-100 supernatant. The evaluation of the blot scans yielded the following distribution of the 218 kD Mi-2 protein: 97.5% in the nucleus (FIG. 7B), 0% each in the mitochondrial and microsomal fractions and 2.5% in the S-100 fraction (FIG. 7C).

FIG. 8A shows immunoprecipitations of ³⁵S-methionine-labeled proteins of HEp-2 cell lysates separated by SDS-PAGE with anti-Mi-2 sera (P2-P12) of DM patients and healthy control persons (C1, C2). b1=protein A SEPHAROSE™ (Amersham Pharmacia Biotech, Inc., Piscataway N.J.) alone. All patient sera precipitated a 235 kD protein and furthermore additional proteins which are marked by asterisks on the right-hand side and have individually differing patterns; the molecular weights are indicated additionally.

FIG. 8B shows an immunoprecipitation of proteins of a HEp-2 cell lysate with the DM patient serum No. 1 (P1), with rMi-2 protein affinity-purified antibodies of serum No. 1 (P1 alg), affinity-purified rabbit antibodies (Ra alg), rabbit-IgG (Ra Ig), rabbit immune serum (Ra IS) and rabbit pre-immune serum (Ra pIS). Affinity-purified anti-rMi-2 antibodies precipitated the same 235 kD protein as the patient-anti-Mi-2-positive serum.

FIG. 8C shows immunoprecipitations of ³⁵S-methionine-labeled proteins of HEp-2 cell nuclei and cytoplasmic fractions of HEp-2 cells with human serum and rabbit serum. b1=protein A SEPHAROSE™ alone; C=serum of a healthy person; P2=patient No. 2; P2 alg=affinity-purified anti-rMi-2-specific IgG of patient No. 2; Ra alg=affinity-purified anti-rMi-2 Ig of the rabbit; Ra IS=rabbit immune serum; Ra pIS=pre-immune serum. Both the patient serum and the rabbit serum precipitated the 235 kD protein from the nuclear extract but not from cytoplasmic fractions. The patterns obtained with affinity-purified human and rabbit antibodies are almost identical.

FIG. 9 shows an immunofluorescence of HEp-2 cells with human and rabbit-anti-Mi-2 serum. This immunofluorescence shows a marked nuclear fluorescence. FIG. 9A1: human anti-Mi-2-positive serum (No. 3, TABLE I). FIG. 9A2: serum of patient No. 9, which was admixed with anti-mitochondrial antibodies, shows nuclear and mitochondrial fluorescence. FIG. 9A3: the pooled serum shown in FIG. 9A2 was affinity purified with rMi-2, which resulted in an exclusive nuclear fluorescence. FIG. B1: rabbit pre-immune serum. FIG. B2: a rabbit serum after the second booster with rMi-2 antigen showed intense nuclear fluorescence. FIG. B3: the affinity-purified rabbit-anti-M2 antibodies dyed the nucleus.

FIG. 10 shows an ELISA with rMi-2 antigen for the detection of anti-218 kD fluorescence. B3: the affinity-purified rabbit-anti-M2 antibodies dyed the nucleus. Mi-2 antibodies. Recesses of microtiter plates were coated with 0.8 μg rMi-2 antigen and blocked with BSA. ODs of series dilutions of anti-Mi-2-positive sera and a control serum are shown. For testing human sera, dilutions of 1:200 were chosen.

FIG. 11 shows the detection of anti-Mi-2 antibodies with the recombinant protein-ELISA. Dashed line: border region (OD 0.5-0.6). The encircled numbers designate the number of tested negative sera having ODs between 0.05 and 0.5. DM: dermatomyositis; SLE: systemic lupus erythematodes; RA: rheumatoid arthritis; ANA positive sera: sera which were submitted for the analysis for ANA and reacted positively with HEp-2 cells (titer 1: ≧160). Controls: sera of healthy persons.

V. DETAILED DESCRIPTION OF THE INVENTION

It is one the object of the present invention to provide means by which dermatomyositis can be detected by way of differential diagnosis.

According to the invention, this is achieved by providing the subject matters in the claims.

Thus, the subject matter of the invention relates to a dermatomyositis-specific auto-antigen which comprises the amino acid sequence of FIGS. 2A-D (SEQ ID NO:2) or a functional derivative or fragment thereof.

The expression “functional derivative or fragment” comprises any derivative or fragment of the amino acid sequence of FIGS. 2A-D (SEQ ID NO:2) against which an autoantibody can be formed. In particular, the expression relates to epitopes in the amino acid sequence which may act as antigens. Also, it is self-evident that the amino acid sequence of FIGS. 2A-D (SEQ ID NO:2) may include additions, substitutions and/or deletions of one or more amino acids, which also applies to the functional derivatives or fragments thereof.

Another subject matter of the invention relates to a nucleic acid coding for an above auto-antigen. This may be an RNA or a DNA. The latter can be e.g., a genomic DNA or a cDNA. Preferred is a DNA which comprises the following:

(a) the DNA of FIGS. 2A-D or a portion thereof,

(b) a DNA hybridizing with the DNA of (a), or

(c) a DNA related to the DNA of (a) or (b) via the degenerated genetic code.

The expression of “hybridizing DNA” refers to a DNA which hybridizes under conventional conditions, particularly 20° C. below the DNA melting point, with a DNA of (a).

The DNA of FIGS. 2A-D was deposited as E. coli Hi-F1-213 under DSM 9800 with the DSM [German-type collection of microorganisms, Mascheroder Weg 1b, D-38124 Braunschweig, Germany] on Mar. 13, 1995.

A DNA according to the invention and an auto-antigen coded by it are referred to below as “Mi-2 DNA” (“Mi-2 cDNA”) and “Mi-2 antigen”, respectively. This is due to the fact that for the production of such a DNA sera from dermatomyositis patients can be used, which are referred to as “anti-Mi-2 positive”. In this connection, “Mi-2” refers to the patient's serum which reacted for the first time with the nuclear extracts from thymocytes of calves or rabbits.

For the preparation of an Mi-2 cDNA it is favorable to screen a lambda phage expression library with the above patient sera. Positive clones may then be sequenced and optionally be used for further screening. The inventive preparation of an Mi-2 cDNA is described in Examples 1 to 2. Its structural elucidation as well as that of the Mi-2 antigen coded by it are described in Examples 3 to 5.

According to the invention of an Mi-2 cDNA may be present in a vector and expression vector, respectively. A person skilled in the art is familiar with examples thereof. In the case of an expression vector for E. coli, these are, e.g., pGEMEX, pUC derivatives, pGEX-2T and pET3b, the latter being preferred. For the expression in yeast e.g., pY100 and Ycpad1 have to be mentioned while for the expression in animal cells e.g, pKCR, pEFBOS, cDM8 and pCEV4 have to be indicated.

The person skilled in the art is familiar with cells suitable to express an Mi-2 cDNA present in an expression vector. Examples of such cells comprise the E. coli strains HB101, DH1, x1776, JM101, JM109 and BL21, the latter being preferred, the yeast strain Saccharomyces cerevisiae and the animal cells L, 3T3, FM3A, CHO, COS, Vero and HeLa.

The person skilled in the art knows in which way an Mi-2 cDNA has to be inserted in an expression vector. He is also familiar with the fact that this DNA can be inserted in combination with a DNA coding for another protein and peptide, respectively, so that the Mi-2 cDNA can be expressed in the form of a fusion protein.

Furthermore, the person skilled in the art knows conditions of cultivating transformed cells and transfected cells, respectively. He is also familiar with processes of isolating and purifying the expressed Mi-2 antigen. Thus, an above, recombinantly prepared Mi-2 antigen (referred to below as rMi-2 antigen) which may also be a fusion protein, also belongs to the subject matter of the invention.

Auto-antigens according to the invention distinguish themselves in that they recognize dermatomyositis-specific autoantibodies. Therefore, they are suited for the differential diagnosis of collagen diseases, particularly of dermatomyositis. Such a diagnosis can be made by common detection methods, particularly a Western blot, an ELISA, an immunoprecipitation or an immunofluorescence. For this purpose, the auto-antigens according to the invention may be labeled, if appropriate, or be used in combination with labeled antibodies directed thereagainst.

Furthermore, auto-antigens according to the invention may be present in a kit. It may contain the auto-antigens, as indicated in the above form, together with conventional additives such as buffers and carrier material. Such a kit also belongs to the subject matter of the invention.

Furthermore, the auto-antigens according to the invention are also suited for therapeutic purposes. For example, they can serve for removing autoantibodies from the circulation of dermatomyositis patients by way of affinity chromatography. One should also have in mind a removal of dermatomyositis-specific autoantibody-producing lymphocytes by linkage of the auto-antigens according to the invention to cell toxins.

Besides, nucleic acids according to the invention, particularly DNAs, are suitable for all kinds of diagnostic purpose.

The below examples explain the invention in more detail. The following preparations and examples are given to enable those skilled in the art to more clearly understand and to practice the present invention. The present invention, however, is not limited in scope by the exemplified embodiments, which are intended as illustrations of single aspects of the invention only, and methods which are functionally equivalent are within the scope of the invention. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims.

VI. EXAMPLES A. Example 1 Screening and Isolation of Recombinant Lambda Phages

The IgG fraction of a human anti-Mi-2-positive serum was isolated by DEAE SEPHAROSE™ chromatography and used for screening about 400 000 plagues of an oligo (dT)-primed HeLa cDNA expression library (λ UNIZAPXR™, Stratagene, Heidelberg, Germany). Following repeated purification, a positive clone was obtained and sequenced. Two 40-^(meric) oligonucleotides which were complementary to the two ends of the insert of this clone (4.3 kb) were used after radioactive labeling for re-screening of the same library to obtain further cDNAs in the 5′ and 3′ directions. Furthermore, even shorter 5′ clones were additionally obtained by an AMPLIFINDER™ RACE kit (Clontech, Palo Alto, Calif.) and cloning into the plasmid BLUESCRIPT KS™ (Stratagene). A total of 15 clones were isolated.

B. Example 2 Sequencing of the Clones and Structure of the Entire Mi-2 cDNA

BLUESCRIPT KS™ plasmids were excised from the λ-clones by means of helper phages according to the manufacturer's instructions (Stratagene) and the DNAs were sequenced following characterization by hybridization and purification using QUIAGEN™ columns (Quiagen GmbH, Düsseldorf, Germany) by means of a sequencing machine (ALF™, Pharmacia, Freiburg, Germany) according to the dideoxy method using fluorescence ATP (Boehringer Mannheim). All sequences of the clones were prepared according to a walking primer strategy, the clones having been sequenced in both directions. The sequence data was combined by means of the ASSEMGEL™ Software of PC-GEne (IntelliGenetics Inc., Brussels, Belgium).

C. Example 3 Nucleotide Sequence and Derived Amino Acid Sequence of the Mi-2 cDNA

Computer-assisted sequence analyses were carried out by means of the GCG Software (Genetics Computer Group, Madison, Wis.). The EMBL nucleic acid and the SWISS-PROT protein sequence data banks were scanned with the BLASTN and BLASTP algorithms (Altschul et al., 1990, J Mol. Biol. 215:403-410) as to the presence of local similarities with individual sequences in the Mi-2 nucleic acid/amino acid sequence. The search for functional motifs was carried out with the PROSITE algorithm. Bairoch, 1991, Nucleic Acids Res. 19:2241-2245, Supplement. The cloning and sequencing strategy yielded the nucleic acid sequence shown in FIGS. 2A-D (SEQ ID NO:1) and the amino acid sequence derived therefrom (SEQ ID NO:2). The first ATG (nt 1) is located in an environment which is favored for translocation initiation and starts an open reading frame of 5736 bp which codes for a protein having 1912 amino acids (217989 Dalton) (218 kD Mi-2 protein).

A sequence motif (AAATAAA) very similar to the polyadenylation-consensus signal (AATAAA) is found in the non-translated 3' region of nt 6143-6151. The 218 kD Mi-2 antigen is a hydrophilic acidic protein (p1=5.48) having almost uniform distribution of charged or polar and hydrophobic amino acids which are embedded in N-glycosylation and N-myrostoylation motifs. Furthermore, there are many potential phosphorylation sites.

The search for sequence similarities between the 218 kD Mi-2 antigen and other proteins did not yield any marked homology with respect to the sequences deposited it the data banks. However, several functional domains in the 218 kD Mi-2 protein could be identified clearly. The most prominent regions are characteristic of helicases and are located in the central portion of the protein. The most striking similarities were shown by 20 proteins all of which belong to a superfamily of helicases, defined by the SNF2 and RAD54 yeast helicases. Bairoch, 1991, supra. located in the central portion of the protein. The most striking similarities waqs shown by 20 proteins all of which belong to a superfamily of helicases, defined by the SNF2 and RAD54 yeast helicases. Bairoch, 1991, supra.

D. Example 4 Size of the Mi-2 mRNA

Total RNA and poly (A)⁺ RNA were isolated from a human cell line, separated electrophoretically in a formaldehyde agarose gel according to their sizes and hybridized with radioactively labeled Mi-2 cDNA after transfer to a membrane. The autoradiograph (FIG. 3) shows a signal at about 6.8 kb. This experiment demonstrates that the Mi-2 mRNA is long enough to comprise the 5.7 kb long Mi-2 cDNA.

E. Example 5 Chromosomal Localization of the 218 kD Mi-2 Gene

A fragment of the Mi-2 cDNA (nt 153-4902) was labeled with biotin-dUTP and used for in situ hybridization of human metaphase chromosomes. Hybridized DNA was detected with a fluorescein isothiocyanate-labeled avidin (Jackson Immuno. Research Laboratories, West Grove, Pa.) and an AXIOPHOT™ photomicroscope (Zeiss, Oberkochen, Germany). Pictures were digitized with a CCD camera (Photometrics, Tuscon, Ariz.) and processed with an APPLE™ computer system (Cupertino, Calif.). Specific fluorescence signals were observed on the distal side of the short arm of chromosome 12 (12p 13). Twelve of eighteen investigated metaphase chromosomes showed specific signals at both homologues).

F. Example 6 Synthesis of Part of the Coding Region of the Mi-2 cDNA in a Bacterial Expression System

A segment in the central portion of the Mi-2 cDNA (nt 1422-2909) (FIGS. 1 and 2) was provided at the 5' end with an NdeI restriction site and at the 3' end with six histidine codons as well as a BamHI restriction site and, following ligation into the bacterial expression vector pET3b, transformed into E. coli BL21 (DE3) pLysS. Studier et al., 1990, Methods Enzymol. 185:60-89. Following the culturing up to an OD₆₀₀ of 0.5, it was induced with 1 mM isopropyl-β-D-thiogalactopyranoside, further cultured for 8 hours and harvested. The cell pellet was suspended in 10 mM Tris-HCl (pH 8.0), 0.1 M sodium phosphate and 8 M urea, and the insoluble material which included the recombinant protein was obtained by centrifugation and dissolved in 8 M urea, 6 M guanidinium-HCl and obtained by means of Ni²⁺ chelate affinity chromatography (Quiagen). The yield was about 200 mg of recombinant protein (rMi-2) per liter of culture. Following evaluation in SDS-PAGE, the size of the Mi-2 antigen corresponded to the derived molecular weight of 55 kD. All of the twelve anti-Mi-2-positive sera from dermatomyositis patients reacted in immunoblots with the rMi-2 antigen (FIG. 6, lane A2, TABLE I).

G. Example 7 rMi-2-Specific Human and Rabbit Sera and Anti-Mi-2 Sera React with the Same Natural Nuclear Protein

Human anti-Mi-2-positive sera (Nos. 1, 2, 9 in TABLE I) and rabbit anti-rMi-2 sera were affinity-purified with rMi-2 antigens immobilized at nitrocellulose membranes. Both antibodies reacted not only with the rMi-2 antigen but also with epitopes of a natural HEp-2 cell nuclear proteins having an Mr 235 kD (FIG. 6). The 235 kD HEp-2 cell nuclear protein reacted in the immunoblot also with most of the anti-Mi-2-positive patient sera. Since both the human and the rabbit anti-rMi-2 immunoglobulines recognized the same nuclear protein as the patient sera, the 218 kD Mi-2 protein represents the main antigen of Mi-2. Differences existing between the molecular weight (M) calculated on the basis of the DNA sequence and the molecular weight (M_(r)) measured by means of SDS-PAGE, as in Mi-2 antigen, are observed frequently.

H. Example 8 Indirect Immunofluorescence Microscopy

All human anti-Mi-2 sera produced a characteristic finely granular nuclear fluorescence by means of HEp-2 cells, in some cases without dyeing the nucleoli. The antibody titers ranged between 1:160 and 1:5120 (FIG. 9, A1, TABLE I). An identical nuclear immunofluorescence pattern was observed with a human anti-Mi-2-positive serum after affinity purification with rMi-2 protein and with the rabbit anti-rMi-2 immunoglobulin.

TABLE I Test Data of Patients Having Anti-Mi-2-Positive-Sera, Obtained by ELISA, Immunoblot, Immunoprecipitation or Immunodiffusion* ANA Titer Immunoblot Immunoprecipitation ELISA HEp-2 Cells rMi-2 nat. Mi-2 ³⁵S-methionine r-Mi-2 Immuno- rez. ver. rez. ver. rez. ver. HEp-2 cells OD diffusion Diagnosis 1 5120 12800  3200** 235 kD pos 1.7 + DM 2 1280 800 <200   235 kD pos 0.9 + DM 3 2560 12800 12800  235 kD pos 2.2 + DM 4 5120 3200 800 235 kD pos 1.7 + DM 5 5120 3200 3200  235 kD pos 1.6 + DM 6 2560 400 <200   235 kD pos 0.8 + DM 7 2560 3200 200 235 kD pos 1.4 + DM 8 320 3200 800 235 kD pos 2.1 + DM 9 2560 3200 200 235 kD pos 1.7 + DM 10 1280 3200 800 235 kD pos 1.4 + DM 11 160 400 <200   235 kD pos 0.4 + DM 12 1280 12800 12800  235 kD pos 2.3 + DM 13 20480 1600 200 235 kD pos 0.8 + SLE, anti-dsDNA positive 14 5120 200 <200   235 kD pos 0.7 ND non-def. collagen disease 15 320 400 <200   235 kD pos 0.6 ND proteinuria, thyroiditis *Nos. 1-12 Comprise patients having defined DM, Nos. 13-15 represent three patients of the ANA positive group (n = 901). rMi-2: recombinant Mi-2 antigen fragment (SEQ ID NO: 1 aa474-969, encoded by nt1422-2909; see Example F); nat Mi-2: major antigen (218 kD Mi-2 antigen, SEQ ID NO: 2) having an electrophoretic migration, corresponding to 235 kD, detected by anti-Mi-2 positive sera in immunoblots of nuclear proteins separated by SDS-PAGE; rez. ver.: reciprocal serum dilution. # Immunoprecipitation: carried out with ³⁵S-methionine-labeled HEp-2 cell extract. Precipitation of a 235 kD nuclear protein with epitopes cross-reacting with the 218 kD Mi-2-antigen. ND: not investigated. **Additional protein band in the blot: 80 kD, rez. ver. 12800

Nos. 1-12 Comprise patients having defined DM, Nos. 13-15 represent three patients of the ANA positive group (n=901). rMi-2: recombinant Mi-2 antigen fragment (SEQ ID NO: 1 aa474-969, encoded by nt1422-2909; see Example F); nat. Mi-2: major antigen (218 D Mi-2 antigen, SEQ ID NO: 2) having an electrophoretic migration, corresponding to 235 kd, detected by anti-Mi-2 positive sera in immunoblots of nuclear proteins separated by SDS-PAGE; rez. ver.: reciprocal serum dilution. Immunoprecipitation: carried out with ³⁵S-methionine-labeled HEp-2 cell extract. Precipitation of a 235 kD nuclear protein with epitopes cross-reacting with the 218 kD Mi-2 antigen. ND: not investigated.

I. Example 9 ELISA for Determining Anti-218 kD Mi-2 Antibodies in Patient Sera

Microtiter plates (Immunolon, Dynatech, Denkendorf) were incubated per recess with 100 μl of a solution consisting of 8 μg/ml rMi-2 antigen and 0.1 M sodium carbonate (pH 9.6) at 4° C. for 16 hours and then blocked per recess with 300 μl of a solution consisting of PBS and 0.1% BSA at 4° C. for 16 hours. Antibody screening was carried out with 200 μl of serum per recess (serum dilutions: 1:300 in PBS, 0.01% Tween and 0.1% BSA) at 37° C. during 30 minutes of incubation. After a wash step (5×PBS, 0.01% Tween, at 37° C. for 30 minutes) each recess was incubated with 200 μl of a peroxidase-labeled rabbit anti-human IgG F(ab′)₂ with 1:2000 dilution in PBS, 0.01% Tween and 0.5% BSA at 37° C. for 30 minutes and washed again. Bound antibodies were visualized with OPD, and the enzyme reaction was stopped with 50 μl 4 M H₂SO₄ per recess. The absorption was measured bichromatically at 492/20 nm. 1368 human sera were tested with this assay (FIG. 10). The mean OD value of a control group of 189 healthy persons was 0.25±0.08: ODs between 0.5 and 0.6 were evaluated to be limiting values, ODs>0.6 were considered positive. The antibody concentrations (ODs) of the twelve anti-Mi-2-positive dermatomyositis patients are listed in FIG. 11. With the exception of one serum, which was negative in the ELISA but positive in the immunoblot assay, all patient sera showed OD values markedly above the limiting value.

All references cited within the body of the instant specification are hereby incorporated by reference in their entirety.

2 1 6328 DNA Homo sapiens CDS (1)...(5736) 1 atg gcg tcg ggc ctg ggc tcc ccg tcc ccc tgc tcg gcg ggc agt gag 48 Met Ala Ser Gly Leu Gly Ser Pro Ser Pro Cys Ser Ala Gly Ser Glu 1 5 10 15 gag gag gat atg gat gca ctt ttg aac aac agc ctg ccc cca ccc cac 96 Glu Glu Asp Met Asp Ala Leu Leu Asn Asn Ser Leu Pro Pro Pro His 20 25 30 cca gaa aat gaa gag gac cca gaa gag gat ttg tca gaa aca gag act 144 Pro Glu Asn Glu Glu Asp Pro Glu Glu Asp Leu Ser Glu Thr Glu Thr 35 40 45 cca aag ctc aag aag aag aaa aag cct aag aaa cct cgg gac cct aaa 192 Pro Lys Leu Lys Lys Lys Lys Lys Pro Lys Lys Pro Arg Asp Pro Lys 50 55 60 atc cct aag agc aag cgc caa aaa aag gag cgt atg ctc tta tgc cgg 240 Ile Pro Lys Ser Lys Arg Gln Lys Lys Glu Arg Met Leu Leu Cys Arg 65 70 75 80 cag ctg ggg gac agc tct ggg gag ggg cca gag ttt gtg gag gag gag 288 Gln Leu Gly Asp Ser Ser Gly Glu Gly Pro Glu Phe Val Glu Glu Glu 85 90 95 gaa gag gtg gct ctg cgc tca gac agt gag ggc agc gac tat act cct 336 Glu Glu Val Ala Leu Arg Ser Asp Ser Glu Gly Ser Asp Tyr Thr Pro 100 105 110 ggc aag aag aag aag aag aag ctt gga cct aag aaa gag aag aag agc 384 Gly Lys Lys Lys Lys Lys Lys Leu Gly Pro Lys Lys Glu Lys Lys Ser 115 120 125 aaa tcc aag cgg aag gag gag gag gag gag gat gat gat gat gat gat 432 Lys Ser Lys Arg Lys Glu Glu Glu Glu Glu Asp Asp Asp Asp Asp Asp 130 135 140 tca aag gag cct aaa tca tct gct cag ctc ctg gaa gac tgg ggc atg 480 Ser Lys Glu Pro Lys Ser Ser Ala Gln Leu Leu Glu Asp Trp Gly Met 145 150 155 160 gaa gac att gac cac gtg ttc tca gag gag gat tat cga acc ctc acc 528 Glu Asp Ile Asp His Val Phe Ser Glu Glu Asp Tyr Arg Thr Leu Thr 165 170 175 aac tac aag gcc ttc agc cag ttt gtc aga ccc ctc att gct gcc aaa 576 Asn Tyr Lys Ala Phe Ser Gln Phe Val Arg Pro Leu Ile Ala Ala Lys 180 185 190 aat ccc aag att gct gtc tcc aag atg atg atg gtt ttg ggt gca aaa 624 Asn Pro Lys Ile Ala Val Ser Lys Met Met Met Val Leu Gly Ala Lys 195 200 205 tgg cgg gag ttc agt acc aat aac ccc ttc aaa ggc agt tct ggg gca 672 Trp Arg Glu Phe Ser Thr Asn Asn Pro Phe Lys Gly Ser Ser Gly Ala 210 215 220 tca gtg gca gct gcg gca gca gca gcg gta gct gtg gtg gag agc atg 720 Ser Val Ala Ala Ala Ala Ala Ala Ala Val Ala Val Val Glu Ser Met 225 230 235 240 gtg aca gcc act gag gtt gca cca cca cct ccc cct gtg gag gtg cct 768 Val Thr Ala Thr Glu Val Ala Pro Pro Pro Pro Pro Val Glu Val Pro 245 250 255 atc cgc aag gcc aag acc aag gag ggc aaa ggt ccc aat gct cgg agg 816 Ile Arg Lys Ala Lys Thr Lys Glu Gly Lys Gly Pro Asn Ala Arg Arg 260 265 270 aag ccc aag ggc agc cct cgt gta cct gat gcc aag aag cct aaa ccc 864 Lys Pro Lys Gly Ser Pro Arg Val Pro Asp Ala Lys Lys Pro Lys Pro 275 280 285 aag aaa gta gct ccc ctg aaa atc aag ctg gga ggt ttt ggt tcc aag 912 Lys Lys Val Ala Pro Leu Lys Ile Lys Leu Gly Gly Phe Gly Ser Lys 290 295 300 cgt aag aga tcc tcg agt gag gat gat gac tta gat gtg gaa tct gac 960 Arg Lys Arg Ser Ser Ser Glu Asp Asp Asp Leu Asp Val Glu Ser Asp 305 310 315 320 ttc gat gat gcc agt atc aat agc tat tct gtt tct gat ggt tcc acc 1008 Phe Asp Asp Ala Ser Ile Asn Ser Tyr Ser Val Ser Asp Gly Ser Thr 325 330 335 agc cgt agt agc cgc agc cgc aag aaa ctc cga acc act aaa aag aaa 1056 Ser Arg Ser Ser Arg Ser Arg Lys Lys Leu Arg Thr Thr Lys Lys Lys 340 345 350 aag aaa ggc gag gag gag gtg act gct gtg gat ggt tat gag aca gac 1104 Lys Lys Gly Glu Glu Glu Val Thr Ala Val Asp Gly Tyr Glu Thr Asp 355 360 365 cac cag gac tat tgc gag gtg tgc cag caa ggc ggt gag atc atc ctg 1152 His Gln Asp Tyr Cys Glu Val Cys Gln Gln Gly Gly Glu Ile Ile Leu 370 375 380 tgt gat acc tgt ccc cgt gct tac cac atg gtc tgc ctg gat ccc gac 1200 Cys Asp Thr Cys Pro Arg Ala Tyr His Met Val Cys Leu Asp Pro Asp 385 390 395 400 atg gag aag gct ccc gag ggc aag tgg agc tgc cca cac tgc gag aag 1248 Met Glu Lys Ala Pro Glu Gly Lys Trp Ser Cys Pro His Cys Glu Lys 405 410 415 gaa ggc atc cag tgg gaa gct aaa gag gac aat tcg gag ggt gag gag 1296 Glu Gly Ile Gln Trp Glu Ala Lys Glu Asp Asn Ser Glu Gly Glu Glu 420 425 430 atc ctg gaa gag gtt ggg gga gac ctc gaa gag gag gat gac cac cat 1344 Ile Leu Glu Glu Val Gly Gly Asp Leu Glu Glu Glu Asp Asp His His 435 440 445 atg gaa ttc tgt cgg gtc tgc aag gat ggt ggg gaa ctg ctc tgc tgt 1392 Met Glu Phe Cys Arg Val Cys Lys Asp Gly Gly Glu Leu Leu Cys Cys 450 455 460 gat acc tgt cct tct tcc tac cac atc cac tgc ctg aat ccc cca ctt 1440 Asp Thr Cys Pro Ser Ser Tyr His Ile His Cys Leu Asn Pro Pro Leu 465 470 475 480 cca gag atc ccc aac ggt gaa tgg ctc tgt ccc cgt tgt acg tgt cca 1488 Pro Glu Ile Pro Asn Gly Glu Trp Leu Cys Pro Arg Cys Thr Cys Pro 485 490 495 gct ctg aag ggc aaa gtg cag aag atc cta atc tgg aag tgg ggt cag 1536 Ala Leu Lys Gly Lys Val Gln Lys Ile Leu Ile Trp Lys Trp Gly Gln 500 505 510 cca cca tct ccc aca cca gtg cct cgg cct cca gat gct gat ccc aac 1584 Pro Pro Ser Pro Thr Pro Val Pro Arg Pro Pro Asp Ala Asp Pro Asn 515 520 525 acg ccc tcc cca aag ccc ttg gag ggg cgg cca gag cgg cag ttc ttt 1632 Thr Pro Ser Pro Lys Pro Leu Glu Gly Arg Pro Glu Arg Gln Phe Phe 530 535 540 gtg aaa tgg caa ggc atg tct tac tgg cac tgc tcc tgg gtt tct gaa 1680 Val Lys Trp Gln Gly Met Ser Tyr Trp His Cys Ser Trp Val Ser Glu 545 550 555 560 ctg cag ctg gag ctg cac tgt cag gtg atg ttc cga aac tat cag cgg 1728 Leu Gln Leu Glu Leu His Cys Gln Val Met Phe Arg Asn Tyr Gln Arg 565 570 575 aag aat gat atg gat gag cca cct tct ggg gac ttt ggt ggt gat gaa 1776 Lys Asn Asp Met Asp Glu Pro Pro Ser Gly Asp Phe Gly Gly Asp Glu 580 585 590 gag aaa agc cga aag cga aag aac aag gac cct aaa ttt gca gag atg 1824 Glu Lys Ser Arg Lys Arg Lys Asn Lys Asp Pro Lys Phe Ala Glu Met 595 600 605 gag gaa cgc ttc tat cgc tat ggg ata aaa ccc gag tgg atg atg atc 1872 Glu Glu Arg Phe Tyr Arg Tyr Gly Ile Lys Pro Glu Trp Met Met Ile 610 615 620 cac cga atc ctc aac cac agt gtg gac aag aag ggc cac gtc cac tac 1920 His Arg Ile Leu Asn His Ser Val Asp Lys Lys Gly His Val His Tyr 625 630 635 640 ttg atc aag tgg cgg gac tta cct tac gat cag gct tct tgg gag agt 1968 Leu Ile Lys Trp Arg Asp Leu Pro Tyr Asp Gln Ala Ser Trp Glu Ser 645 650 655 gag gat gtg gag atc cag gat tac gac ctg ttc aag cag agc tat tgg 2016 Glu Asp Val Glu Ile Gln Asp Tyr Asp Leu Phe Lys Gln Ser Tyr Trp 660 665 670 aat cac agg gag tta atg agg ggt gag gaa ggc cga cca ggc aag aag 2064 Asn His Arg Glu Leu Met Arg Gly Glu Glu Gly Arg Pro Gly Lys Lys 675 680 685 ctc aag aag gtg aag ctt cgg aag ttg gag agg cct cca gaa acg cca 2112 Leu Lys Lys Val Lys Leu Arg Lys Leu Glu Arg Pro Pro Glu Thr Pro 690 695 700 aca gtt gat cca aca gtg aag tat gag cga cag cca gag tac ctg gat 2160 Thr Val Asp Pro Thr Val Lys Tyr Glu Arg Gln Pro Glu Tyr Leu Asp 705 710 715 720 gct aca ggt gga acc ctg cac ccc tat caa atg gag ggc ctg aat tgg 2208 Ala Thr Gly Gly Thr Leu His Pro Tyr Gln Met Glu Gly Leu Asn Trp 725 730 735 ttg cgc ttc tcc tgg gct cag ggc act gac acc atc ttg gct gat gag 2256 Leu Arg Phe Ser Trp Ala Gln Gly Thr Asp Thr Ile Leu Ala Asp Glu 740 745 750 atg ggc ctt ggg aaa act gta cag aca gca gtc ttc ctg tat tcc ctt 2304 Met Gly Leu Gly Lys Thr Val Gln Thr Ala Val Phe Leu Tyr Ser Leu 755 760 765 tac aag gag ggt cat tcc aaa ggc ccc ttc cta gtg agc gcc cct ctt 2352 Tyr Lys Glu Gly His Ser Lys Gly Pro Phe Leu Val Ser Ala Pro Leu 770 775 780 tct acc atc atc aac tgg gag cgg gag ttt gaa atg tgg gct cca gac 2400 Ser Thr Ile Ile Asn Trp Glu Arg Glu Phe Glu Met Trp Ala Pro Asp 785 790 795 800 atg tat gtc gta acc tat gtg ggt gac aag gac agc cgt gcc atc atc 2448 Met Tyr Val Val Thr Tyr Val Gly Asp Lys Asp Ser Arg Ala Ile Ile 805 810 815 cga gag aat gag ttc tcc ttt gaa gac aat gcc att cgt ggt ggc aag 2496 Arg Glu Asn Glu Phe Ser Phe Glu Asp Asn Ala Ile Arg Gly Gly Lys 820 825 830 aag gcc tcc cgc atg aag aaa gag gca tct gtg aaa ttc cat gtg ctg 2544 Lys Ala Ser Arg Met Lys Lys Glu Ala Ser Val Lys Phe His Val Leu 835 840 845 ctg aca tcc tat gaa ttg atc acc att gac atg gct att ttg ggc tct 2592 Leu Thr Ser Tyr Glu Leu Ile Thr Ile Asp Met Ala Ile Leu Gly Ser 850 855 860 att gat tgg gcc tgc ctc atc gtg gat gaa gcc cat cgg ctg aag aac 2640 Ile Asp Trp Ala Cys Leu Ile Val Asp Glu Ala His Arg Leu Lys Asn 865 870 875 880 aat cag tct aag ttc ttc cgg gta ttg aat ggt tac tca ctc cag cac 2688 Asn Gln Ser Lys Phe Phe Arg Val Leu Asn Gly Tyr Ser Leu Gln His 885 890 895 aag ctg ttg ctg act ggg aca cca tta caa aac aat ctg gaa gag ttg 2736 Lys Leu Leu Leu Thr Gly Thr Pro Leu Gln Asn Asn Leu Glu Glu Leu 900 905 910 ttt cat ctg ctc aac ttt ctc acc ccc gag agg ttc cac aat ttg gaa 2784 Phe His Leu Leu Asn Phe Leu Thr Pro Glu Arg Phe His Asn Leu Glu 915 920 925 ggt ttt ttg gag gag ttt gct gac att gcc aag gag gac cag ata aaa 2832 Gly Phe Leu Glu Glu Phe Ala Asp Ile Ala Lys Glu Asp Gln Ile Lys 930 935 940 aaa ctg cat gac atg ctg ggg ccg cac atg ttg cgg cgg ctc aaa gcc 2880 Lys Leu His Asp Met Leu Gly Pro His Met Leu Arg Arg Leu Lys Ala 945 950 955 960 gat gtg ttc aag aac atg ccc tcc aag aca gaa cta att gtg cgt gtg 2928 Asp Val Phe Lys Asn Met Pro Ser Lys Thr Glu Leu Ile Val Arg Val 965 970 975 gag ctg agc cct atg cag aag aaa tac tac aag tac atc ctc act cga 2976 Glu Leu Ser Pro Met Gln Lys Lys Tyr Tyr Lys Tyr Ile Leu Thr Arg 980 985 990 aat ttt gaa gca ctc aat gcc cga ggt ggt ggc aac cag gtg tct ctg 3024 Asn Phe Glu Ala Leu Asn Ala Arg Gly Gly Gly Asn Gln Val Ser Leu 995 1000 1005 ctg aat gtg gtg atg gat ctt aag aag tgc tgc aac cat cca tac ctc 3072 Leu Asn Val Val Met Asp Leu Lys Lys Cys Cys Asn His Pro Tyr Leu 1010 1015 1020 ttc cct gtg gct gca atg gaa gct cct aag atg cct aat ggc atg tat 3120 Phe Pro Val Ala Ala Met Glu Ala Pro Lys Met Pro Asn Gly Met Tyr 1025 1030 1035 1040 gat ggc agt gcc cta atc aga gca tct ggg aaa tta ttg ctg ctg cag 3168 Asp Gly Ser Ala Leu Ile Arg Ala Ser Gly Lys Leu Leu Leu Leu Gln 1045 1050 1055 aaa atg ctc aag aac ctt aag gag ggt ggg cat cgt gta ctc atc ttt 3216 Lys Met Leu Lys Asn Leu Lys Glu Gly Gly His Arg Val Leu Ile Phe 1060 1065 1070 tcc cag atg acc aag atg cta gac ctg cta gag gat ttc ttg gaa cat 3264 Ser Gln Met Thr Lys Met Leu Asp Leu Leu Glu Asp Phe Leu Glu His 1075 1080 1085 gaa ggt tat aaa tac gaa cgc atc gat ggt gga atc act ggg aac atg 3312 Glu Gly Tyr Lys Tyr Glu Arg Ile Asp Gly Gly Ile Thr Gly Asn Met 1090 1095 1100 cgg caa gag gcc att gac cgc ttc aat gca ccg ggt gct cag cag ttc 3360 Arg Gln Glu Ala Ile Asp Arg Phe Asn Ala Pro Gly Ala Gln Gln Phe 1105 1110 1115 1120 tgc ttc ttg ctt tcc act cga gct ggg ggc ctt gga atc aat ctg gcc 3408 Cys Phe Leu Leu Ser Thr Arg Ala Gly Gly Leu Gly Ile Asn Leu Ala 1125 1130 1135 act gct gac aca gtt att atc tat gac tct gac tgg aac ccc cat aat 3456 Thr Ala Asp Thr Val Ile Ile Tyr Asp Ser Asp Trp Asn Pro His Asn 1140 1145 1150 gac att cag gcc ttt agc aga gct cac cgg att ggg caa aat aaa aag 3504 Asp Ile Gln Ala Phe Ser Arg Ala His Arg Ile Gly Gln Asn Lys Lys 1155 1160 1165 gta atg atc tac cgg ttt gtg acc cgt gcg tca gtg gag gag cgc atc 3552 Val Met Ile Tyr Arg Phe Val Thr Arg Ala Ser Val Glu Glu Arg Ile 1170 1175 1180 acg cag gtg gca aag aag aaa atg atg ctg acg cat cta gtg gtg cgg 3600 Thr Gln Val Ala Lys Lys Lys Met Met Leu Thr His Leu Val Val Arg 1185 1190 1195 1200 cct ggg ctg ggc tcc aag act gga tct atg tcc aaa cag gag ctt gat 3648 Pro Gly Leu Gly Ser Lys Thr Gly Ser Met Ser Lys Gln Glu Leu Asp 1205 1210 1215 gat atc ctc aaa ttt ggc act gag gaa cta ttc aag gat gaa gcc act 3696 Asp Ile Leu Lys Phe Gly Thr Glu Glu Leu Phe Lys Asp Glu Ala Thr 1220 1225 1230 gat gga gga gga gac aac aaa gag gga gaa gat agc agt gtt atc cac 3744 Asp Gly Gly Gly Asp Asn Lys Glu Gly Glu Asp Ser Ser Val Ile His 1235 1240 1245 tac gat gat aag gcc att gaa cgg ctg cta gac cgt aac cag gat gag 3792 Tyr Asp Asp Lys Ala Ile Glu Arg Leu Leu Asp Arg Asn Gln Asp Glu 1250 1255 1260 act gaa gac aca gaa ttg cag ggc atg aat gaa tat ttg agc tca ttc 3840 Thr Glu Asp Thr Glu Leu Gln Gly Met Asn Glu Tyr Leu Ser Ser Phe 1265 1270 1275 1280 aaa gtg gcc cag tat gtg gta cgg gaa gaa gaa atg ggg gag gaa gag 3888 Lys Val Ala Gln Tyr Val Val Arg Glu Glu Glu Met Gly Glu Glu Glu 1285 1290 1295 gag gta gaa cgg gaa atc att aaa cag gaa gaa agt gtg gat cct gac 3936 Glu Val Glu Arg Glu Ile Ile Lys Gln Glu Glu Ser Val Asp Pro Asp 1300 1305 1310 tac tgg gag aaa ttg ctg cgg cac cat tat gag cag cag caa gaa gat 3984 Tyr Trp Glu Lys Leu Leu Arg His His Tyr Glu Gln Gln Gln Glu Asp 1315 1320 1325 cta gcc cga aat ctg ggc aaa gga aaa aga atc cgt aaa cag gtc aac 4032 Leu Ala Arg Asn Leu Gly Lys Gly Lys Arg Ile Arg Lys Gln Val Asn 1330 1335 1340 tac aat gat ggc tcc cag gag gac cga gat tgg cag gac gac cag tcc 4080 Tyr Asn Asp Gly Ser Gln Glu Asp Arg Asp Trp Gln Asp Asp Gln Ser 1345 1350 1355 1360 gac aac cag tcc gat tac tca gtg gct tca gag gaa ggt gat gaa gac 4128 Asp Asn Gln Ser Asp Tyr Ser Val Ala Ser Glu Glu Gly Asp Glu Asp 1365 1370 1375 ttt gat gaa cgt tca gaa gct ccc cgt agg ccc agt cgt aag ggc ctg 4176 Phe Asp Glu Arg Ser Glu Ala Pro Arg Arg Pro Ser Arg Lys Gly Leu 1380 1385 1390 cgg aat gat aaa gat aag cca ttg cct cct ctg ttg gcc cgt gtt ggt 4224 Arg Asn Asp Lys Asp Lys Pro Leu Pro Pro Leu Leu Ala Arg Val Gly 1395 1400 1405 ggg aat att gaa gta ctt ggt ttt aat gct cgt cag cga aaa gcc ttt 4272 Gly Asn Ile Glu Val Leu Gly Phe Asn Ala Arg Gln Arg Lys Ala Phe 1410 1415 1420 ctt aat gca att atg cga tat ggt atg cca cct cag gat gct ttt act 4320 Leu Asn Ala Ile Met Arg Tyr Gly Met Pro Pro Gln Asp Ala Phe Thr 1425 1430 1435 1440 acc cag tgg ctt gta aga gac ctg cga ggc aaa tca gag aaa gag ttc 4368 Thr Gln Trp Leu Val Arg Asp Leu Arg Gly Lys Ser Glu Lys Glu Phe 1445 1450 1455 aag gca tat gtc tct ctt ttc atg cgg cat tta tgt gag ccg ggg gca 4416 Lys Ala Tyr Val Ser Leu Phe Met Arg His Leu Cys Glu Pro Gly Ala 1460 1465 1470 gat ggg gct gag acc ttt gct gat ggt gtc ccc cga gaa ggc ctg tct 4464 Asp Gly Ala Glu Thr Phe Ala Asp Gly Val Pro Arg Glu Gly Leu Ser 1475 1480 1485 cgc cag cat gtc ctt act aga att ggt gtt atg tct ttg att cgc aag 4512 Arg Gln His Val Leu Thr Arg Ile Gly Val Met Ser Leu Ile Arg Lys 1490 1495 1500 aag gtt cag gag ttt gaa cat gtt aat ggg cgc tgg agc atg cct gaa 4560 Lys Val Gln Glu Phe Glu His Val Asn Gly Arg Trp Ser Met Pro Glu 1505 1510 1515 1520 ctg gct gag gtg gag gaa aac aag aag atg tcc cag cca ggg tca ccc 4608 Leu Ala Glu Val Glu Glu Asn Lys Lys Met Ser Gln Pro Gly Ser Pro 1525 1530 1535 tcc cca aaa act cct aca ccc tcc act cca ggg gac acg cag ccc aac 4656 Ser Pro Lys Thr Pro Thr Pro Ser Thr Pro Gly Asp Thr Gln Pro Asn 1540 1545 1550 act cct gca cct gtc cca cct gct gaa gat ggg ata aaa ata gag gaa 4704 Thr Pro Ala Pro Val Pro Pro Ala Glu Asp Gly Ile Lys Ile Glu Glu 1555 1560 1565 aat agc ctc aaa gaa gaa gag agc ata gaa gga gaa aag gag gtt aaa 4752 Asn Ser Leu Lys Glu Glu Glu Ser Ile Glu Gly Glu Lys Glu Val Lys 1570 1575 1580 tct aca gcc cct gag act gcc att gag tgt aca cag gcc cct gcc cct 4800 Ser Thr Ala Pro Glu Thr Ala Ile Glu Cys Thr Gln Ala Pro Ala Pro 1585 1590 1595 1600 gcc tca gag gat gaa aag gtc gtt gtt gaa ccc cct gag gga gag gag 4848 Ala Ser Glu Asp Glu Lys Val Val Val Glu Pro Pro Glu Gly Glu Glu 1605 1610 1615 aaa gtg gaa aag gca gag gtg aag gag aga aca gag gaa cct atg gag 4896 Lys Val Glu Lys Ala Glu Val Lys Glu Arg Thr Glu Glu Pro Met Glu 1620 1625 1630 aca gag ccc aaa ggt gct gct gat gta gag aag gtg gag gaa aag tca 4944 Thr Glu Pro Lys Gly Ala Ala Asp Val Glu Lys Val Glu Glu Lys Ser 1635 1640 1645 gca ata gat ctg acc cct att gtg gta gaa gac aaa gaa gag aag aaa 4992 Ala Ile Asp Leu Thr Pro Ile Val Val Glu Asp Lys Glu Glu Lys Lys 1650 1655 1660 gaa gaa gaa gag aaa aaa gag gtg atg ctt cag aat gga gag acc ccc 5040 Glu Glu Glu Glu Lys Lys Glu Val Met Leu Gln Asn Gly Glu Thr Pro 1665 1670 1675 1680 aag gac ctg aat gat gag aaa cag aag aaa aat att aaa caa cgt ttc 5088 Lys Asp Leu Asn Asp Glu Lys Gln Lys Lys Asn Ile Lys Gln Arg Phe 1685 1690 1695 atg ttt aac att gca gat ggt ggt ttt act gag ttg cac tcc ctt tgg 5136 Met Phe Asn Ile Ala Asp Gly Gly Phe Thr Glu Leu His Ser Leu Trp 1700 1705 1710 cag aat gaa gag cgg gca gcc aca gtt acc aag aag act tat gag atc 5184 Gln Asn Glu Glu Arg Ala Ala Thr Val Thr Lys Lys Thr Tyr Glu Ile 1715 1720 1725 tgg cat cga cgg cat gac tac tgg ctg cta gcc ggc att ata aac cat 5232 Trp His Arg Arg His Asp Tyr Trp Leu Leu Ala Gly Ile Ile Asn His 1730 1735 1740 ggc tat gcc cgg tgg caa gac atc cag aat gac cca cgc tat gcc atc 5280 Gly Tyr Ala Arg Trp Gln Asp Ile Gln Asn Asp Pro Arg Tyr Ala Ile 1745 1750 1755 1760 ctc aat gag cct ttc aag ggt gaa atg aac cgt ggc aat ttc tta gag 5328 Leu Asn Glu Pro Phe Lys Gly Glu Met Asn Arg Gly Asn Phe Leu Glu 1765 1770 1775 atc aag aat aaa ttt cta gct cga agg ttt aag ctc tta gaa caa gct 5376 Ile Lys Asn Lys Phe Leu Ala Arg Arg Phe Lys Leu Leu Glu Gln Ala 1780 1785 1790 ctg gtg att gag gaa cag ctg cgc cgg gct gct tac ttg aac atg tca 5424 Leu Val Ile Glu Glu Gln Leu Arg Arg Ala Ala Tyr Leu Asn Met Ser 1795 1800 1805 gaa gac cct tct cac cct tcc atg gcc ctc aac acc cgc ttt gct gag 5472 Glu Asp Pro Ser His Pro Ser Met Ala Leu Asn Thr Arg Phe Ala Glu 1810 1815 1820 gtg gag tgt ttg gcg gaa agt cat cag cac ctg tcc aag gag tca atg 5520 Val Glu Cys Leu Ala Glu Ser His Gln His Leu Ser Lys Glu Ser Met 1825 1830 1835 1840 gca gga aac aag cca gcc aat gca gtc ctg cac aaa gtt ctg aaa cag 5568 Ala Gly Asn Lys Pro Ala Asn Ala Val Leu His Lys Val Leu Lys Gln 1845 1850 1855 ctg gaa gaa ctg ctg agt gac atg aaa gct gat gtg act cga ctc cca 5616 Leu Glu Glu Leu Leu Ser Asp Met Lys Ala Asp Val Thr Arg Leu Pro 1860 1865 1870 gct acc att gcc cga att ccc cca gtt gct gtg agg tta cag atg tca 5664 Ala Thr Ile Ala Arg Ile Pro Pro Val Ala Val Arg Leu Gln Met Ser 1875 1880 1885 gag cgt aac att ctc agc cgc ctg gca aac cgg gca ccc gaa cct acc 5712 Glu Arg Asn Ile Leu Ser Arg Leu Ala Asn Arg Ala Pro Glu Pro Thr 1890 1895 1900 cca cag cag gta gcc cag cag cag tgaagatgca gactgatacc acctccaccg 5766 Pro Gln Gln Val Ala Gln Gln Gln 1905 1910 ctgagcagtg accttcctca ctttctcttg tcccagcttc tcccctgggg gcctgagaga 5826 ccctcacctt ccttctgccc atcttccatg ttgtaaagga acagccccag tgcactgggg 5886 gaggggaggg agtgaggggc agtggtgccc ttcctgcaga agagacatgc agcagtagcg 5946 ctggcgccat ctgcaggagc tggcgggctg gccttctgga ccctggcttc tccccactgt 6006 aacgcctgtt acacacaaac tgttgtgggt tcctgccagg cttgaagaaa atgatctgaa 6066 ttttttcctc cttttggttt tattttgttg gtttattttg tgttttcttt tctccttttt 6126 ggggggtatt cagagtgggc tgggcccctg ggcgagacac agctacctct gttggcatct 6186 ttttaatacc aggaacccag cggctctagc cactgagcgg ctaaatgaaa taaagtggaa 6246 aaaaaaaaaa aaggaaaaaa ccaaaagcat aaaaaaccac agcaaatttc ttgatgaaaa 6306 ttgaaaataa aagtttcctt gt 6328 2 1912 PRT Homo sapiens 2 Met Ala Ser Gly Leu Gly Ser Pro Ser Pro Cys Ser Ala Gly Ser Glu 1 5 10 15 Glu Glu Asp Met Asp Ala Leu Leu Asn Asn Ser Leu Pro Pro Pro His 20 25 30 Pro Glu Asn Glu Glu Asp Pro Glu Glu Asp Leu Ser Glu Thr Glu Thr 35 40 45 Pro Lys Leu Lys Lys Lys Lys Lys Pro Lys Lys Pro Arg Asp Pro Lys 50 55 60 Ile Pro Lys Ser Lys Arg Gln Lys Lys Glu Arg Met Leu Leu Cys Arg 65 70 75 80 Gln Leu Gly Asp Ser Ser Gly Glu Gly Pro Glu Phe Val Glu Glu Glu 85 90 95 Glu Glu Val Ala Leu Arg Ser Asp Ser Glu Gly Ser Asp Tyr Thr Pro 100 105 110 Gly Lys Lys Lys Lys Lys Lys Leu Gly Pro Lys Lys Glu Lys Lys Ser 115 120 125 Lys Ser Lys Arg Lys Glu Glu Glu Glu Glu Asp Asp Asp Asp Asp Asp 130 135 140 Ser Lys Glu Pro Lys Ser Ser Ala Gln Leu Leu Glu Asp Trp Gly Met 145 150 155 160 Glu Asp Ile Asp His Val Phe Ser Glu Glu Asp Tyr Arg Thr Leu Thr 165 170 175 Asn Tyr Lys Ala Phe Ser Gln Phe Val Arg Pro Leu Ile Ala Ala Lys 180 185 190 Asn Pro Lys Ile Ala Val Ser Lys Met Met Met Val Leu Gly Ala Lys 195 200 205 Trp Arg Glu Phe Ser Thr Asn Asn Pro Phe Lys Gly Ser Ser Gly Ala 210 215 220 Ser Val Ala Ala Ala Ala Ala Ala Ala Val Ala Val Val Glu Ser Met 225 230 235 240 Val Thr Ala Thr Glu Val Ala Pro Pro Pro Pro Pro Val Glu Val Pro 245 250 255 Ile Arg Lys Ala Lys Thr Lys Glu Gly Lys Gly Pro Asn Ala Arg Arg 260 265 270 Lys Pro Lys Gly Ser Pro Arg Val Pro Asp Ala Lys Lys Pro Lys Pro 275 280 285 Lys Lys Val Ala Pro Leu Lys Ile Lys Leu Gly Gly Phe Gly Ser Lys 290 295 300 Arg Lys Arg Ser Ser Ser Glu Asp Asp Asp Leu Asp Val Glu Ser Asp 305 310 315 320 Phe Asp Asp Ala Ser Ile Asn Ser Tyr Ser Val Ser Asp Gly Ser Thr 325 330 335 Ser Arg Ser Ser Arg Ser Arg Lys Lys Leu Arg Thr Thr Lys Lys Lys 340 345 350 Lys Lys Gly Glu Glu Glu Val Thr Ala Val Asp Gly Tyr Glu Thr Asp 355 360 365 His Gln Asp Tyr Cys Glu Val Cys Gln Gln Gly Gly Glu Ile Ile Leu 370 375 380 Cys Asp Thr Cys Pro Arg Ala Tyr His Met Val Cys Leu Asp Pro Asp 385 390 395 400 Met Glu Lys Ala Pro Glu Gly Lys Trp Ser Cys Pro His Cys Glu Lys 405 410 415 Glu Gly Ile Gln Trp Glu Ala Lys Glu Asp Asn Ser Glu Gly Glu Glu 420 425 430 Ile Leu Glu Glu Val Gly Gly Asp Leu Glu Glu Glu Asp Asp His His 435 440 445 Met Glu Phe Cys Arg Val Cys Lys Asp Gly Gly Glu Leu Leu Cys Cys 450 455 460 Asp Thr Cys Pro Ser Ser Tyr His Ile His Cys Leu Asn Pro Pro Leu 465 470 475 480 Pro Glu Ile Pro Asn Gly Glu Trp Leu Cys Pro Arg Cys Thr Cys Pro 485 490 495 Ala Leu Lys Gly Lys Val Gln Lys Ile Leu Ile Trp Lys Trp Gly Gln 500 505 510 Pro Pro Ser Pro Thr Pro Val Pro Arg Pro Pro Asp Ala Asp Pro Asn 515 520 525 Thr Pro Ser Pro Lys Pro Leu Glu Gly Arg Pro Glu Arg Gln Phe Phe 530 535 540 Val Lys Trp Gln Gly Met Ser Tyr Trp His Cys Ser Trp Val Ser Glu 545 550 555 560 Leu Gln Leu Glu Leu His Cys Gln Val Met Phe Arg Asn Tyr Gln Arg 565 570 575 Lys Asn Asp Met Asp Glu Pro Pro Ser Gly Asp Phe Gly Gly Asp Glu 580 585 590 Glu Lys Ser Arg Lys Arg Lys Asn Lys Asp Pro Lys Phe Ala Glu Met 595 600 605 Glu Glu Arg Phe Tyr Arg Tyr Gly Ile Lys Pro Glu Trp Met Met Ile 610 615 620 His Arg Ile Leu Asn His Ser Val Asp Lys Lys Gly His Val His Tyr 625 630 635 640 Leu Ile Lys Trp Arg Asp Leu Pro Tyr Asp Gln Ala Ser Trp Glu Ser 645 650 655 Glu Asp Val Glu Ile Gln Asp Tyr Asp Leu Phe Lys Gln Ser Tyr Trp 660 665 670 Asn His Arg Glu Leu Met Arg Gly Glu Glu Gly Arg Pro Gly Lys Lys 675 680 685 Leu Lys Lys Val Lys Leu Arg Lys Leu Glu Arg Pro Pro Glu Thr Pro 690 695 700 Thr Val Asp Pro Thr Val Lys Tyr Glu Arg Gln Pro Glu Tyr Leu Asp 705 710 715 720 Ala Thr Gly Gly Thr Leu His Pro Tyr Gln Met Glu Gly Leu Asn Trp 725 730 735 Leu Arg Phe Ser Trp Ala Gln Gly Thr Asp Thr Ile Leu Ala Asp Glu 740 745 750 Met Gly Leu Gly Lys Thr Val Gln Thr Ala Val Phe Leu Tyr Ser Leu 755 760 765 Tyr Lys Glu Gly His Ser Lys Gly Pro Phe Leu Val Ser Ala Pro Leu 770 775 780 Ser Thr Ile Ile Asn Trp Glu Arg Glu Phe Glu Met Trp Ala Pro Asp 785 790 795 800 Met Tyr Val Val Thr Tyr Val Gly Asp Lys Asp Ser Arg Ala Ile Ile 805 810 815 Arg Glu Asn Glu Phe Ser Phe Glu Asp Asn Ala Ile Arg Gly Gly Lys 820 825 830 Lys Ala Ser Arg Met Lys Lys Glu Ala Ser Val Lys Phe His Val Leu 835 840 845 Leu Thr Ser Tyr Glu Leu Ile Thr Ile Asp Met Ala Ile Leu Gly Ser 850 855 860 Ile Asp Trp Ala Cys Leu Ile Val Asp Glu Ala His Arg Leu Lys Asn 865 870 875 880 Asn Gln Ser Lys Phe Phe Arg Val Leu Asn Gly Tyr Ser Leu Gln His 885 890 895 Lys Leu Leu Leu Thr Gly Thr Pro Leu Gln Asn Asn Leu Glu Glu Leu 900 905 910 Phe His Leu Leu Asn Phe Leu Thr Pro Glu Arg Phe His Asn Leu Glu 915 920 925 Gly Phe Leu Glu Glu Phe Ala Asp Ile Ala Lys Glu Asp Gln Ile Lys 930 935 940 Lys Leu His Asp Met Leu Gly Pro His Met Leu Arg Arg Leu Lys Ala 945 950 955 960 Asp Val Phe Lys Asn Met Pro Ser Lys Thr Glu Leu Ile Val Arg Val 965 970 975 Glu Leu Ser Pro Met Gln Lys Lys Tyr Tyr Lys Tyr Ile Leu Thr Arg 980 985 990 Asn Phe Glu Ala Leu Asn Ala Arg Gly Gly Gly Asn Gln Val Ser Leu 995 1000 1005 Leu Asn Val Val Met Asp Leu Lys Lys Cys Cys Asn His Pro Tyr Leu 1010 1015 1020 Phe Pro Val Ala Ala Met Glu Ala Pro Lys Met Pro Asn Gly Met Tyr 1025 1030 1035 1040 Asp Gly Ser Ala Leu Ile Arg Ala Ser Gly Lys Leu Leu Leu Leu Gln 1045 1050 1055 Lys Met Leu Lys Asn Leu Lys Glu Gly Gly His Arg Val Leu Ile Phe 1060 1065 1070 Ser Gln Met Thr Lys Met Leu Asp Leu Leu Glu Asp Phe Leu Glu His 1075 1080 1085 Glu Gly Tyr Lys Tyr Glu Arg Ile Asp Gly Gly Ile Thr Gly Asn Met 1090 1095 1100 Arg Gln Glu Ala Ile Asp Arg Phe Asn Ala Pro Gly Ala Gln Gln Phe 1105 1110 1115 1120 Cys Phe Leu Leu Ser Thr Arg Ala Gly Gly Leu Gly Ile Asn Leu Ala 1125 1130 1135 Thr Ala Asp Thr Val Ile Ile Tyr Asp Ser Asp Trp Asn Pro His Asn 1140 1145 1150 Asp Ile Gln Ala Phe Ser Arg Ala His Arg Ile Gly Gln Asn Lys Lys 1155 1160 1165 Val Met Ile Tyr Arg Phe Val Thr Arg Ala Ser Val Glu Glu Arg Ile 1170 1175 1180 Thr Gln Val Ala Lys Lys Lys Met Met Leu Thr His Leu Val Val Arg 1185 1190 1195 1200 Pro Gly Leu Gly Ser Lys Thr Gly Ser Met Ser Lys Gln Glu Leu Asp 1205 1210 1215 Asp Ile Leu Lys Phe Gly Thr Glu Glu Leu Phe Lys Asp Glu Ala Thr 1220 1225 1230 Asp Gly Gly Gly Asp Asn Lys Glu Gly Glu Asp Ser Ser Val Ile His 1235 1240 1245 Tyr Asp Asp Lys Ala Ile Glu Arg Leu Leu Asp Arg Asn Gln Asp Glu 1250 1255 1260 Thr Glu Asp Thr Glu Leu Gln Gly Met Asn Glu Tyr Leu Ser Ser Phe 1265 1270 1275 1280 Lys Val Ala Gln Tyr Val Val Arg Glu Glu Glu Met Gly Glu Glu Glu 1285 1290 1295 Glu Val Glu Arg Glu Ile Ile Lys Gln Glu Glu Ser Val Asp Pro Asp 1300 1305 1310 Tyr Trp Glu Lys Leu Leu Arg His His Tyr Glu Gln Gln Gln Glu Asp 1315 1320 1325 Leu Ala Arg Asn Leu Gly Lys Gly Lys Arg Ile Arg Lys Gln Val Asn 1330 1335 1340 Tyr Asn Asp Gly Ser Gln Glu Asp Arg Asp Trp Gln Asp Asp Gln Ser 1345 1350 1355 1360 Asp Asn Gln Ser Asp Tyr Ser Val Ala Ser Glu Glu Gly Asp Glu Asp 1365 1370 1375 Phe Asp Glu Arg Ser Glu Ala Pro Arg Arg Pro Ser Arg Lys Gly Leu 1380 1385 1390 Arg Asn Asp Lys Asp Lys Pro Leu Pro Pro Leu Leu Ala Arg Val Gly 1395 1400 1405 Gly Asn Ile Glu Val Leu Gly Phe Asn Ala Arg Gln Arg Lys Ala Phe 1410 1415 1420 Leu Asn Ala Ile Met Arg Tyr Gly Met Pro Pro Gln Asp Ala Phe Thr 1425 1430 1435 1440 Thr Gln Trp Leu Val Arg Asp Leu Arg Gly Lys Ser Glu Lys Glu Phe 1445 1450 1455 Lys Ala Tyr Val Ser Leu Phe Met Arg His Leu Cys Glu Pro Gly Ala 1460 1465 1470 Asp Gly Ala Glu Thr Phe Ala Asp Gly Val Pro Arg Glu Gly Leu Ser 1475 1480 1485 Arg Gln His Val Leu Thr Arg Ile Gly Val Met Ser Leu Ile Arg Lys 1490 1495 1500 Lys Val Gln Glu Phe Glu His Val Asn Gly Arg Trp Ser Met Pro Glu 1505 1510 1515 1520 Leu Ala Glu Val Glu Glu Asn Lys Lys Met Ser Gln Pro Gly Ser Pro 1525 1530 1535 Ser Pro Lys Thr Pro Thr Pro Ser Thr Pro Gly Asp Thr Gln Pro Asn 1540 1545 1550 Thr Pro Ala Pro Val Pro Pro Ala Glu Asp Gly Ile Lys Ile Glu Glu 1555 1560 1565 Asn Ser Leu Lys Glu Glu Glu Ser Ile Glu Gly Glu Lys Glu Val Lys 1570 1575 1580 Ser Thr Ala Pro Glu Thr Ala Ile Glu Cys Thr Gln Ala Pro Ala Pro 1585 1590 1595 1600 Ala Ser Glu Asp Glu Lys Val Val Val Glu Pro Pro Glu Gly Glu Glu 1605 1610 1615 Lys Val Glu Lys Ala Glu Val Lys Glu Arg Thr Glu Glu Pro Met Glu 1620 1625 1630 Thr Glu Pro Lys Gly Ala Ala Asp Val Glu Lys Val Glu Glu Lys Ser 1635 1640 1645 Ala Ile Asp Leu Thr Pro Ile Val Val Glu Asp Lys Glu Glu Lys Lys 1650 1655 1660 Glu Glu Glu Glu Lys Lys Glu Val Met Leu Gln Asn Gly Glu Thr Pro 1665 1670 1675 1680 Lys Asp Leu Asn Asp Glu Lys Gln Lys Lys Asn Ile Lys Gln Arg Phe 1685 1690 1695 Met Phe Asn Ile Ala Asp Gly Gly Phe Thr Glu Leu His Ser Leu Trp 1700 1705 1710 Gln Asn Glu Glu Arg Ala Ala Thr Val Thr Lys Lys Thr Tyr Glu Ile 1715 1720 1725 Trp His Arg Arg His Asp Tyr Trp Leu Leu Ala Gly Ile Ile Asn His 1730 1735 1740 Gly Tyr Ala Arg Trp Gln Asp Ile Gln Asn Asp Pro Arg Tyr Ala Ile 1745 1750 1755 1760 Leu Asn Glu Pro Phe Lys Gly Glu Met Asn Arg Gly Asn Phe Leu Glu 1765 1770 1775 Ile Lys Asn Lys Phe Leu Ala Arg Arg Phe Lys Leu Leu Glu Gln Ala 1780 1785 1790 Leu Val Ile Glu Glu Gln Leu Arg Arg Ala Ala Tyr Leu Asn Met Ser 1795 1800 1805 Glu Asp Pro Ser His Pro Ser Met Ala Leu Asn Thr Arg Phe Ala Glu 1810 1815 1820 Val Glu Cys Leu Ala Glu Ser His Gln His Leu Ser Lys Glu Ser Met 1825 1830 1835 1840 Ala Gly Asn Lys Pro Ala Asn Ala Val Leu His Lys Val Leu Lys Gln 1845 1850 1855 Leu Glu Glu Leu Leu Ser Asp Met Lys Ala Asp Val Thr Arg Leu Pro 1860 1865 1870 Ala Thr Ile Ala Arg Ile Pro Pro Val Ala Val Arg Leu Gln Met Ser 1875 1880 1885 Glu Arg Asn Ile Leu Ser Arg Leu Ala Asn Arg Ala Pro Glu Pro Thr 1890 1895 1900 Pro Gln Gln Val Ala Gln Gln Gln 1905 1910 

What is claimed:
 1. A method for diagnosing an autoimmune disease related to the presence of a dermatomyositis-specific autoantibody in a subject, comprising the steps of: (a) contacting in a first reaction a test sample from the subject with a dermatomyositis-specific autoantigen comprising the amino acid sequence of SEQ ID NO:2 under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a first immunological complex; (b) contacting in a second reaction a control sample with the autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a second immunological complex; (c) detecting the first immunological complex in the first reaction and the second immunological complex in the second reaction; and (d) comparing the amount of the first immunological complex in the first reaction with the amount of the second immunological complex in the second reaction; wherein a greater amount of the first immunological complex in the first reaction than of the second immunological complex in the second reaction indicates that the subject has the autoimmune disease.
 2. A method for diagnosing an autoimmune disease related to the presence of a dermatomyositis-specific autoantibody in a subject, comprising the steps of: (a) contacting in a first reaction a test sample from the subject with a dermatomyositis-specific autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a first immunological complex; (b) contacting in a second reaction a control sample with the autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a second immunological complex; (c) detecting the first immunological complex in the first reaction and the second immunological complex in the second reaction; and (d) comparing the amount of the first immunological complex in the first reaction with the amount of the second immunological complex in the second reaction;  wherein a greater amount of the first immunological complex in the first reaction than of the second immunological complex in the second reaction indicates that the subject has the autoimmune disease and the dermatomyositis-specific autoantigen comprises an isolated polypeptide encoded by a polynucleotide selected from the group consisting of: (i) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 1422 through nucleotide number 2909; (ii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 153 through nucleotide number 4902; (iii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 649 through nucleotide number 4891; (iv) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 1931 through nucleotide number 4881; (v) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 2204 through nucleotide number 4888; (vi) a polynucleotide consisting of the sequence as shown in SEQ ID NO: 1 from nucleotide number 3224 through nucleotide number 4888; (vii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3620 through nucleotide number 4888; (viii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3666 through nucleotide number 6155; (ix) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3843 through nucleotide number 6239; and (x) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3967 through nucleotide number
 6155. 3. A method for diagnosing an autoimmune disease related to the presence of a dermatomyositis-specific autoantibody in a subject, comprising the steps of (a) contacting in a first reaction a test sample from the subject with a dermatomyositis-specific autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a first immunological complex; (b) contacting in a second reaction a control sample with the autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a second immunological complex; (c) detecting the first immunological complex in the first reaction and the second immunological complex in the second reaction; and (d) comparing the amount of the first immunological complex in the first reaction with the amount of the second immunological complex in the second reaction;  wherein a greater amount of the first immunological complex in the first reaction than of the second immunological complex in the second reaction indicates that the subject has the autoimmune disease and the dermatomyositis-specific autoantigen comprises an isolated polypeptide selected from the group consisting of: (i) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 54 through amino acid residue number 74; (ii) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 114 through amino acid residue number 134; (iii) a polypeptide consisting of the sequence as shown in SEQ D NO:2 from amino acid residue number 134 through amino acid residue number 144; (iv) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 258 through amino acid residue number 288; (v) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 748 through amino acid residue number 759; (vi) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 783 through amino acid residue number 794; (vii) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 870 through amino acid residue number 878; (viii) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 898 through amino acid residue number 911; (ix) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 944 through amino acid residue number 960; (x) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 950 through amino acid residue number 961; (xi) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 1122 through amino acid residue number 1145; and (xii) a polypeptide consisting of the sequence as shown in SEQ ID NO:2 from amino acid residue number 1150 through amino acid residue number
 1184. 4. A method for diagnosing an autoimmune disease related to the presence of a dermatomyositis-specific autoantibody in a subject, comprising the steps of (a) contacting in a first reaction a test sample from the subject with a dermatomyositis-specific autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a first immunological complex; (b) contacting in a second reaction a control sample with the autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a second immunological complex; (c) detecting the first immunological complex in the first reaction and the second immunological complex in the second reaction; and (d) comparing the amount of the first immunological complex in the first reaction with the amount of the second immunological complex in the second reaction;  wherein a greater amount of the first immunological complex in the first reaction than of the second immunological complex in the second reaction indicates that the subject has the autoimmune disease and the dermatomyositis-specific autoantigen comprises an isolated polypeptide encoded by a polynucleotide that hybridizes at 20° C. below the DNA melting point to the complement of: (i) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 1422 through nucleotide number 2909; (ii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 153 through nucleotide number 4902; (iii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 649 through nucleotide number 4891; (iv) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 1931 through nucleotide number 4881; (v) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 2204 through nucleotide number 4888; (vi) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3224 through nucleotide number 4888; (vii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3620 through nucleotide number 4888; (viii) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3666 through nucleotide number 6155; (ix) a polynucleotide consisting of the sequence as shown in SEQ ID NO:1 from nucleotide number 3843 through nucleotide number 6239; or (x) a polynucleotide consisting of the sequence as shown in SEQ ID NO: 1 from nucleotide number 3967 through nucleotide number 6155;  wherein said isolated polypeptide binds to an autoantibody from a dermatomyositis patient.
 5. A method for diagnosing an autoimmune disease related to the presence of a dermatomyositis-specific autoantibody in a subject, comprising the steps of (a) contacting in a first reaction a test sample from the subject with a dermatomyositis-specific autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a first immunological complex; (b) contacting in a second reaction a control sample with the autoantigen under conditions that allow the autoantigen and the dermatomyositis-specific autoantibody to form a second immunological complex; (c) detecting the first immunological complex in the first reaction and the second immunological complex in the second reaction; and (d) comparing the amount of the first immunological complex in the first reaction with the amount of the second immunological complex in the second reaction; wherein a greater amount of the first immunological complex in the first reaction than of the second immunological complex in the second reaction indicates that the subject has the autoimmune disease and the dermatomyositis-specific autoantigen comprises an isolated polypeptide encoded by a polynucleotide that hybridizes at 20° C. below the DNA melting point to the complement of a polynucleotide encoding the amino acid sequence of SEQ ID NO:2 wherein said isolated polypeptide binds to an autoantibody from a dermatomyositis patient. 